This invention relates to locks for space closures. It relates particularly to locks for sliding patio doors and is described herein with particular reference to that application, although no limitation thereby is intended. The principle of the lock is applicable as well to other types of space closures, such as swinging doors, windows, and containers.
It is the general purpose of the present invention to provide a lock which is versatile in its application to a variety of closure types; which may be installed de novo or as a "piggyback" lock for existing closures; which is tamper proof; which permits partial opening of the closure for ventilation purposes without loss of security; which may be quickly and easily unlocked even under panic conditions and even by the very young or the incapacitated; which does not require a special key for its operation; and which is simple in construction, inexpensive to manufacture, and easily installed.
The lock of my invention providing the aforesaid and other advantages broadly comprises a door knob or other rotary actuator, mounting means for mounting the actuator on the door, and a shaft connected for rotary movement to the actuator.
At least one spring-biased bolt rod is mounted on the door for reciprocation between door-locking and door-unlocking positions. A crank is driven by the actuator and connected to the bolt rod. The crank shifts the bolt rod to its spring-biased, door-locking position.
Stops are positioned to stop the movement of the crank in the locking and unlocking positions of the bolt rod, respectively.
A pair of meshing gears or other rotary interengaging means releasably connects the crank to the shaft assembly. A latch maintains the spring-biased bolt rod releasably in its door-locking position.
Trip means are arranged for disengaging the rotary interengaging means when the bolt rod is in its spring-biased, door-locking position, thereby effectuating automatic unlocking of the door by the means biasing the bolt rod.